RIG PROCESSESRIG PROCESSES Drilling, Coring, Directional Drilling, Coring, Directional

Drilling & Survey.Drilling & Survey. Tripping, Wash & Ream, Fishing.Tripping, Wash & Ream, Fishing. E- Logging.E- Logging. Casing & Cementing.Casing & Cementing. Perforating &Testing.Perforating &Testing. Acidizing & Fracturing.Acidizing & Fracturing.

Drilling & CoringDrilling & Coring

Normal Drilling.Normal Drilling. Coring; Convetional Coring:Coring; Convetional Coring: Core headCore head core barrelcore barrel

TrippingTripping((Pulling out or running the string in hole ))((Pulling out or running the string in hole ))

• Normal tripping.Normal tripping.• Tight Hole.Tight Hole.• Wash and Ream.Wash and Ream.• Normal Drag.Normal Drag.• Overpull.Overpull.• Twist off.Twist off.• StuckStuck• FishingFishing

II. Stuck pipeII. Stuck pipe

Drilling string Drilling string cannot be raised, cannot be raised, lowered or rotate.lowered or rotate.

Mechanisms of stuck pipeMechanisms of stuck pipe

Differential Stuck.Differential Stuck. Wellbore Geometry.Wellbore Geometry. Hole packing off.Hole packing off.

A. Differential StuckA. Differential Stuck

Sticking of pipe against a permeable Sticking of pipe against a permeable formation as the result of the pressure of formation as the result of the pressure of the mud in the hole exceeding the bore the mud in the hole exceeding the bore

fluid pressure.fluid pressure.

Differential stickingDifferential sticking

Stuck breadth = 4”Stuck breadth = 4” Stuck length = 25’Stuck length = 25’ Fm pressure = 4000 psiFm pressure = 4000 psi H pressure = 5000 psiH pressure = 5000 psi D. F=4*25*12*(5000-4000)D. F=4*25*12*(5000-4000)

1,200,0001,200,000lbslbs

Key SeatKey Seat

Causes:Causes: Abrupt change in Abrupt change in

angle or direction in angle or direction in soft formations.soft formations.

High string tension High string tension and pipe rotation and pipe rotation wears a slot into the wears a slot into the formation.formation.

While POOH the drill While POOH the drill collars jam into the collars jam into the slot.slot.

Formation cuttings cavings or medium to large Formation cuttings cavings or medium to large pieces of hard formation, cement or junk settle pieces of hard formation, cement or junk settle around the drill string and pack off/bridging the around the drill string and pack off/bridging the

annulus.annulus. Settled cuttingsSettled cuttings Shale instability +Shale instability + Unconsolidated formationsUnconsolidated formations Fractured formationsFractured formations Cement related.Cement related. Junk.Junk.

C. Packing Off & BridgingC. Packing Off & Bridging

Settled Cutting Straight Hole Settled Cutting Straight Hole

Causes:Causes:

• Low annular velocity Low annular velocity and/or poor mud and/or poor mud properties.properties.

• When circulation is When circulation is stopped, the stopped, the cuttings fall back cuttings fall back down the hole and down the hole and pack off the drill pack off the drill string.string.

Settled Cutting Deviated Hole Settled Cutting Deviated Hole

Causes:Causes:

• Drill cuttings settle on Drill cuttings settle on the low side forming a the low side forming a cutting bed.cutting bed.

• The cutting bed builds The cutting bed builds and slide down hole.and slide down hole.

• While POOH the While POOH the cuttings is dragged cuttings is dragged upward by the BHAupward by the BHA

ELECTRIC LOGGINGELECTRIC LOGGING

Logging While Drilling (MWD).Logging While Drilling (MWD). Post Drilling E- Logging.Post Drilling E- Logging. GammaGamma ResistivityResistivity Neutron Density.Neutron Density. Sonic.Sonic.

ResistivityResistivity1000

1500

2000

2500

3000

3500

0.1 1 10

RILD (ohm.m)

TV

D (

m)

NCT

Top Overpressure

1000

1500

2000

2500

3000

3500

100 1000Sonic (usec/m)

TV

D (

m)

Top of Overpressure

NCT

responsein casing

Cycle Skipping

SonicSonic

Casing is steel pipe placed in an oil or gas well at the end of every drilled phase, and then cemented in place prior to striating drilling the lower smaller hole section.

CASINGCASING

Function Of CasingFunction Of Casing Printing hole from caving or collapsingPrinting hole from caving or collapsing Privinting loss of drilling fluids into weak Privinting loss of drilling fluids into weak

formations.formations. Isolate troublesome formations.Isolate troublesome formations. Prevent communication between Prevent communication between

formations.formations. Provides means of extracting Provides means of extracting

hydrocarbons hydrocarbons Provides a means of support for the Provides a means of support for the

wellhead equipment.wellhead equipment.

Casing AccessoriesCasing AccessoriesCentralizers:Centralizers: attached to the casing and

since they have a bowed spring arrangement keep the casing centred in the hole after it is lowered in. Centralised casing can make for a better cement job later.

ScratchersScratchers Float collarsFloat collars

CementingCementing

Well CompletionWell Completion

– Completing the well & Setting Production Completing the well & Setting Production Casing.Casing.

– Perforating production casing.Perforating production casing.– Drill Stem Test (DST).Drill Stem Test (DST).– Acidizing.Acidizing.– Fracturing.Fracturing.– Installing the Christmas Tree.Installing the Christmas Tree.

THANK YOUTHANK YOU